caa a22 4500 46579193X CHVBK 20180323112027.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1007/BF00306405 doi (NATIONALLICENCE)springer-10.1007/BF00306405 Magma mixing in the subvolcanic environment: petrology of the Gerena interaction zone near Seville, Spain [Elektronische Daten] [Antonio Castro, Jesús de la Rosa, W. Stephens] The mechanisms by which felsic and mafic magmas interact and approach a uniform hybrid composition through the processes of mingling and mixing have been studied in a high-level subvolcanic setting in the Spanish Hercynian at Gerena, near Seville. The compositions involved are calc-alkaline and the situation is one of tonalite-quartz diorite synplutonic dykes injected into a granitic magma chamber. The resulting hybrids include dykes, pillows and globules of tonalite with chilled margins which are variously disrupted and homogenised with the host granite. The present investigation is based on field and petrographic observations of hybridization textures, the identification of different stages in the crystallisation history of the tonalite through mineral textures, and the characterization of mineral compositions at these various stages. Proportions of the end-member magmas involved were obtained by major-oxide mixing models and tested satisfactorily with trace elements. A mechanistic model is presented to account for these observations which involves the early quenching of the tonalite when it was emplaced into the granite magma chamber. After high temperature crystallization had occurred the two magmas attained thermal equilibrium and disruption of the tonalite in the high energy regime of this subvolcanic complex resulted in dispersion of fragments and crystals through the granite giving rise to hybrid granodiorite compositions. It is argued that such high-energy flow conditions are a necessary requirement for effective hybridization in this environment in contrast to most large-scale magma chamber settings where mixing is driven by thermal and buoyancy contrasts. Springer-Verlag, 1990 Castro Antonio Departamento de Geología y Minería, Universidad de Sevilla, E-21819, La Rábida, Huelva, Spain aut de la Rosa Jesús Departamento de Geología y Minería, Universidad de Sevilla, E-21819, La Rábida, Huelva, Spain aut Stephens W. Geology Division, University of St. Andrews, St. Andrews, KY16 9ST, Fife, Scotland aut Contributions to Mineralogy and Petrology Springer-Verlag 106/1(1990-12-01), 9-26 0010-7999 106:1<9 1990 106 410 https://doi.org/10.1007/BF00306405 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00306405 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Castro Antonio Departamento de Geología y Minería, Universidad de Sevilla, E-21819, La Rábida, Huelva, Spain aut NATIONALLICENCE 700 1- de la Rosa Jesús Departamento de Geología y Minería, Universidad de Sevilla, E-21819, La Rábida, Huelva, Spain aut NATIONALLICENCE 700 1- Stephens W. Geology Division, University of St. Andrews, St. Andrews, KY16 9ST, Fife, Scotland aut NATIONALLICENCE 773 0- Contributions to Mineralogy and Petrology Springer-Verlag 106/1(1990-12-01), 9-26 0010-7999 106:1<9 1990 106 410 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer